Alarm system.



W. H. GABEL.

ALARM SYSTEM.

APPLICATION FILED JULY 3. I915.

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ALARM SYSTEM.

APPLICATION FILED lULY 3,1915.

Patented Aug. 29, 1916.

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WILZBUR H. GAIBEL, OF KINTYRE, NORTH DAKOTA.

ALARM SYSTEM.

Specification of Letters Patent.

Patented Aug. 29, 1916..

Application filed July 3, 1915. Serial No. 37,886.

To all to 7mm it may concern Be it known that I, WILBUR I'I. GABEL, a citizen of the United States, residing at Iiintyre, in the county of Emmons and State of North Dakota, have invented new and useful Improvements in Alarm Systems, of which the following is a specification.

This invention relates to an alarm apparatus and more particularly to a system wherein the parts will not be rendered inoperative upon cutting of the circuit wires by an unauthorized person.

An object of the invention is the arrangement of the circuits, switches, and electromagnets, whereby, upon increasing the current flow of the circuit, the alarm will be sounded.

The invention consists in the features of construction, combination, and arrangement of parts, hereinafter fully described and claimed, reference being had to the accompanying drawings, in which Figure 1 is a diagrammatic view of the system showing the signal portion of the alarm within the house and the circuit closing apparatus arranged in an outroom. Fig. 2 is a similar view illustrating how the apparatus is protected against being made inoperative by the cutting of the main. Fig. 3 is a vertical section through the casing showing the circuit closing apparatus. Fig. 4: is a vertical transverse section. Fig. 5 is a horizontal section; and, Fig. 6 is a detail view. Fig. "I is a diagrammatic view similar to Figs. 1 and 2 showing the lever arranged in the main circuit so that upon energization of the magnet, the main circuit will be broken.

In the drawings, I have illustrated only one main leading from the outbuilding 1 to the house 2, the terminals being grounded, but I wish it to be understood, if found necessary, that a metallic return can be substituted.

The numeral 3 designates a normally closed circuit that extends from the outbuilding 1 to the house 2 having its terminals grounded as indicated at 3 and i. This circuit includes a source of current 5 and circuit closers 6 and 7 that may be so arranged that upon opening of a door or window, they .will be moved to inoperative position for dec'nergizing the electro-magnet 8.

The alarm circuit is shown at 9 and in cludes a source of current 10, a switch 11, and an electric bell 12, or other audible signals. This circuit has its continuity interrupted at 13, the terminals of which are so arranged as to be bridged by a blade 1 1 having attached thereto an armature under the control of the magnet 8 heretofore mentioned.

For normally spacing the armature a slight distance from the magnet, against the action of the magnetism, I provide a resilient arm 16 rigidly secured to one side of a casing 18. The tension of this resilient arm can be increased in any suitable manner, such as by a threaded rod 19 passing through an L-shaped bracket 20 against which bears the nut 21 threaded upon one extremity of the rod. From this arrangement, it will be seen that by increasing the tension of the arm 16, through the rod and nut heretofore mentioned, the magnetism of the magnet will be unable to attract the armature 15 into engagement with its pole, when the magnet is supplied from the current of the battery 5, but, immediately extra current is supplied to the line, such as by an unauthorized person, as illustrated in Fig. 2, the attraction of the magnet will predominate for moving the armature into engagement with its pole and at the same time giving the resilient arm a lateral movement. This lateral movement of the arm 16 causes it to move from under a lever 22 which gravitates down upon a stationary contact 23 for closing a shunt circuit 24 arranged across the normally closed circuit 3.

When this takes place, it will be readily seen I that the electro-magnet will be short circuited for allowing the switch blade 1 1 to gravitate downwardly and close the alarm circuit previously mentioned.

In the diagrammatic View Fig. 1, I have shown the lever 22 controlling the continuity of a shunt'circuit arranged to short circuit the magnet. In Fig. 2 I have shown the same arrangement with an extra source of current connected to the main circuit such as will be applied by an unauthorized person when the main circuit is cut at the point 3*.

In the diagrammatic view Fig. 7, I have arranged a lever 22 in the main circuit so that upon movement thereof, the main circuit will be broken for deenergizing the magnet 8.

Having described the invention, what is claimed is:

1. In an alarm system, two circuits, an

electro-magnet arranged in one circuit, an alarm device arranged in the other circuit, batteries for energizing each of saidcircuits, a switch arranged in one of the circuits and under the control of said magnet, a resilient arm for spacing the movable member of said switch a slight distance from said magnet, and means for short-circuiting said magnet upon an increase of current passing therethrough.

2. In an alarm system, two circuits, an electro magnet arranged in one circuit, an alarm device arranged in the other circuit, batteries for energizing each of said circuits, a switch arranged in one of the circuits and under the control of said magnet, a resilient armfor spacing the movable member of said switch a slight distance from said magnet, means for short-circuiting said magnet upon an increase of current passing therethrough, and means for varying the tension'of said resilient arm.

3. In an alarm system comprising a normally energized circuit, an alarm circuit, an electro-magnet in said normally energized circuit, a switch blade arranged in said alarm circuit and under the control of said electro-magnet, a resilient arm arranged transversely of said electro-magnet and adapted to space said switch arm a slight distance from the pole of said electromagnet, a screw for adjusting the tension of said resilient arm, and a partial circuit adapted to be closed upon movement of said arm in one direction.

4. In an alarm system comprising a normally energized circuit, an alarm circuit, an electro-magnet in said normally energized circuit, a switch blade arranged in said alarm circuit and under the control of said electro-magnet, a resilient arm arranged transversely of said electro-magnet and adapted to space said switch arm a slight distance from the pole of said electromagnet, a screw for adjusting the tension of said resilient arm, a partial circuit bridging said normally closed circuit, a switch arranged therein and adapted to be closed upon movement of said resilient arm in one direction.

In testimony whereof I aflix in presence of two witnesses.

WILBUR H. GABEL. Witnesses H. 13., TYsoN, FRED E. DAVIS.

my signature Copies of this patent, may be obtained for five cents each,. by addressing the Commissioner of Patents, Washington, D. 0. 

